pin down
US /pɪn daʊn/
UK /pɪn daʊn/

1.
identificar, definir
to understand or describe something exactly
:
•
It's hard to pin down the exact cause of the problem.
É difícil identificar a causa exata do problema.
•
I can't quite pin down what's bothering me.
Não consigo identificar exatamente o que me incomoda.
2.
imobilizar, prender
to make someone stay in a particular place or prevent them from moving
:
•
The police managed to pin down the suspect in the alley.
A polícia conseguiu imobilizar o suspeito no beco.
•
The heavy rain pinned us down in the cabin for hours.
A chuva forte nos prendeu na cabana por horas.